The invention relates to a method and a device for stamping a non-planar surface of a body with a transfer layer of a hot-stamping foil. It further relates to a method for putting a planar foil portion into a non-planar form.
Conventionally, with a method for stamping a non-planar surface of a body with a transfer layer of a hot-stamping foil, first the body to be stamped (the workpiece), which is typically made of plastic, is laid manually on a holding apparatus, in particular a workpiece carrier, wherein the workpiece is preferably clamped. The workpiece holder is then moved into a position in which stamping is to be carried out. The hot-stamping foil is brought into position in that it is clamped, by means of a clamping frame, above the workpiece surface that is to be stamped when this clamping frame is moved into an operating position. Applying a negative pressure to the foil has the effect that the foil follows the shape of the surface contour of the workpiece. Only then is the actual stamping procedure completed, by pressing on the stamping die (which typically comprises a stamping unit made of silicone). Once the stamping procedure has finished, the clamping frame is moved back into its starting position, then the workpiece holder is also moved back into its corresponding starting position, and the stamped workpiece is removed.
A method of this kind has the constant problem that the formation of folds and wrinkles in the hot-stamping foil or in the stamped-on transfer layer is to be prevented.